Effects of electro-acupuncture on expressions of interleukin-1 β and matrix metalloproteinase-1 in rabbit knee osteoarthritis model

Objective: To observe the changes of interleukin-1β(IL-1β) from joint irrigation and matrix metalloproteinase-1(MMP-1) from cartilage expressed in rabbit's knee osteoarthritis(KOA) model before and after electro-acupuncture(EA) treatment, to explore the mechanism of EA treatment on knee osteoarthritis. Method: Thirty healthy New Zealand big-ear rabbits were randomly divided into normal group, model group and EA group. In the latter two groups left knees were fixed in extension position with plaster cast for 6 weeks to establish KOA models. The EA group was treated for 14d. The changes of content of IL-1β expression in joint irrigation after modeling and treatment and changes of MMP-1 expression in cartilage of left condylus after treatment were observed respectively. Result: The radioimmunoassay detection results revealed IL-1β expression in joint irrigation of model group and EA group after modeling were significantly higher than that of control group (P0.05), while the IL-1β expression in model group was significantly higher than that in EA group after treatment (P0.05). By immunohistochemical detection, the MMP-1 positive rates of model group and EA group were significantly higher than that of control group (P0.05), with a higher rate in model group(P0.05). Conclusion: EA treatment can effectively improve the rabbit's KOA, the mechanism of which is probably related with IL-1β reduction in joint and MMP-1 decrease in cartilage so as to, prevent the collagen Ⅱ and proteoglycan from degradation, promote new collagen Ⅱ and proteoglycan formation, improve blood and qi circulation, thus promote the absorption of joint exudates and cartilage repair.